Light emitting diodes (LEDs) are an energy efficient, highly reliable technology that is finding considerable utility in replacing fluorescent lamps in many lighting applications. Fluorescent lamps have become a less desirable source for energy efficient lighting applications since they emit light in 360 degrees. This makes it hard to efficiently direct all of the emitted light to the intended usable area of the lighting application. However, while LEDs are more energy efficient, they present their own design challenges for lighting applications. Specifically, LEDs are point sources as opposed to continuous/extended sources of light. This concentration of point source light needs to be evenly dispersed and distributed across the intended usable area for the lighting application. In addition, since LEDs are point sources requiring dispersion in lighting applications, dispersed LED light will travel across a wide range of angles that will either be: (1) absorbed within the luminaire and create efficiency loss; (2) redirected out of the luminaire but beyond the intended usable area; (3) redirected out of the luminaire but unevenly distributed in the intended usable area, or (4) redirected out of the luminaire and evenly distributed across the intended usable area. Therefore, there are difficult design challenges to properly dispersing light from a row of LEDs into a useful and efficient light distribution. LED luminaire designs that fail to achieve even dispersion and distribution across the intended usable area, and fail to account for the wide range of angles for emitted light, will yield poor performance, including unacceptable glare and poor aesthetics in those lighting applications.
A need exists for a low cost luminaire configuration that efficiently redistributes the point source illumination from LEDs into a light output distribution superior to the inefficient distribution achieved with fluorescent lamps and existing LED luminaires. Specifically, there is a need for a new and more efficient luminaire that offers an even distribution of luminance across its luminous surface, evenly distributes light over a wide footprint below the luminaire, and for which the form factor and conformal geometry of the luminaire is similar to what was designed for traditional/conventional fluorescent lamps.